This invention relates to a key assigner for use in an electronic musical instrument.
A prior art key assigner employed in an electronic musical instrument capable of producing a plurality of tones simultaneously is constructed in such a manner that key switches are scanned sequentially and repetitively by a high rate clock to produce ON-OFF information of the key switches which information is a key data signal representing depressed keys by existence of pulses at allotted time slots of time shared multiplexing and that such key data are respectively assigned to time shared channel in digital code fashion, the number of the channels being equal to a maximum number of tones to be available simultaneously. According to this prior art key assigner, detection of the ON-OFF states of the respective keys is conducted in a predetermined order with a result that an undesirable time lag occurs between the actual ON-OFF operations of the key switches and the detection of the same. The prior art key assigner requires a complicated keyboard circuit for scanning the key switches in a predetermined order. Further, the key assigner needs a relatively high rate of clock pulse for the high rate scanning. This naturally requires a high manufacturing cost.